Methods

Instance methods

First of all, you need to know that the method call name depends on what type your method returns:

Name	Return type
callObjectMethod	JObject
callBooleanMethod	Bool
callByteMethod	Int8
callCharMethod	UInt16
callShortMethod	Int16
callIntMethod	Int32
callLongMethod	Int64
callFloatMethod	Float
callDoubleMethod	Double
callVoidMethod	Void

Then you have a choice of wether to call it on env which is a bit more complex or call it on an object much shorter convenience way.

Calling method that returns an object

The way with env:

let env = JEnv.current()
let methodId = clazz.methodId(
    env: env,
    name: "getSomeObject",
    signature: .returning(.object("com/mylib/mypackage/SomeObject"))
)
let returningClazz = JClass.load("com/mylib/mypackage/SomeObject")
let resultObject = env.callObjectMethod(
    object: object,
    methodId: methodId,
    returningClass: returningClazz
)

The way with object:

let returningClazz = JClass.load("com/mylib/mypackage/SomeObject")
let resultObject = object.callObjectMethod(
    name: "getSomeObject",
    returningClass: returningClazz
)

So the difference is that you don't have to get the methodID yourself, as it is handled automatically under the hood. You also have the option to not pass the env.

Note

The way with object is always shorter than with env

Calling method that pass an object and returns nothing

The way with env:

let env = JEnv.current()
let methodId = clazz.methodId(
    env: env,
    name: "setSomeObject",
    signature: .init(
        .object("com/mylib/mypackage/SomeObject"),
        returning: .void // optional, .void by default
    )
)
let resultObject = env.callVoidMethod(
    object: object,
    methodId: methodId,
    args: [someObject.object]
)

The way with object:

object.callVoidMethod(
    name: "setSomeObject",
    args: someObject.signed(as: "com/mylib/mypackage/SomeObject")
    // or just someObject if you sure that automatic class is correct
)

It is even shorter than the getter.

Calling method that pass a string and returns nothing

The way with object:

object.callVoidMethod(
    name: "setString",
    args: "Hello" // or "Hello".wrap().signedAsString()
    // or "Hello".signedAsCharSequence()
)
// String is always signed as java/lang/String by default

Static methods

Calling static method that returns an object

The way with env:

let env = JEnv.current()
let methodId = clazz.staticMethodId(
    name: "getSomeObject",
    signature: .returning(.object("com/mylib/mypackage/SomeObject"))
)
let returningClazz = JClass.load("com/mylib/mypackage/SomeObject")
let resultObject = env.callStaticObjectMethod(
    clazz: clazz,
    methodId: methodId,
    returningClass: returningClazz
)

The way with clazz:

let returningClazz = JClass.load("com/mylib/mypackage/SomeObject")
let resultObject = clazz.staticObjectMethod(
    name: "getSomeObject",
    returningClass: returningClazz
)